Which one of the following mineral is the main source of Boron in soils
Tourmaline is the main source of boron; Pyrolusite is a mineral consisting essentially of manganese dioxide (MnO2) and is important as an ore of manganese; Magnetite is a mineral whose primary component is an iron oxide that contains equal amounts of iron(II) and iron(III); Muscovite is the most common mineral of the mica family.